Interactive information systems allow an information provider to broadcast information to a user, and in some cases allow a user to send a response to a response collector. The user may receive the information on a wide variety of devices, such as a pager, cellular telephone, personal digital assistant or a television. An interactive information system on which the user receives the information using a television is called an interactive television system.
An interactive television system can enhance the television viewing experience. An interactive television system allows an information provider to broadcast information to users for viewing on their television systems, and defines how a user is allowed to control the time, order or type of information displayed, or other aspects of the application or the user's environment. An interactive television system may allow the user to send to a response collector responses to the information received, or new information.
Some capabilities which could be provided using interactive information systems require the use of broadcaster information which can be specific to a group of users, a broadcaster or an information provider. Broadcaster information includes broadcast channels available to the user, the broadcast frequency corresponding to the channel, call letters corresponding to a broadcaster on the channel, network identifiers for the broadcasters, or interactive information protocol or location information for a broadcast or an application.
For example, to provide an interactive information system capability which lists a channel guide of available cable television channels, it is necessary to identify which channels a user is capable of receiving. This information varies among cable systems, making it difficult to provide this capability to an interactive user community which spans multiple cable systems. To provide an interactive information system capability which allows a user to change television channels by indicating a desired network or station call letters, it is necessary to know which channels are used to carry the desired station, or which channels are used to carry the desired network's programming. Channel information varies among cable systems, and network information varies among geographic region, making it difficult to provide this capability to an interactive user community which spans multiple cable systems or geographic regions.
Some interactive information systems which utilize a variety of methods to broadcast interactive information may require certain information in order to operate properly. For example, one broadcaster may broadcast interactive information on a frequency unrelated to the broadcast program, and another broadcaster may broadcast interactive information in the same frequency as the broadcast program. Identification of the program broadcast frequency, interactive information broadcast frequency and data transport mechanism may be necessary to coordinate broadcast programs with the interactive applications which relate to the program. Some interactive information may be broadcast unrelated to any broadcast program, and it is desirable to allow the user to access this information in a manner similar to accessing broadcast channels.
Knowledge of the interactive information broadcast frequency may not be adequate to obtain the interactive information. For example, some interactive information systems use the vertical blanking interval, or VBI, to transport the interactive information to the user. The VBI is a portion of the television picture which is broadcast, but not typically seen by the television viewer, and readily allows for insertion of data, such as closed captioning text. However, the various portions, or lines, of the VBI may be used for different purposes, and the use of the VBI may vary in various geographic regions, making a uniform placement of interactive data difficult or impossible. It may be necessary for an interactive information system which uses the VBI or other transport to identify the precise VBI or other transport location of the interactive information.
Interactive information system applications may not only relate to the content of a broadcast program, they may also relate to one another. To allow interactive information system applications to interact with one another, it may be necessary to identify the broadcast location of the interactive data for other applications. A broadcast location may include frequency and transport information, such as VBI line.
Many interactive information system protocols may be used to broadcast interactive information. To allow an interactive information system to utilize various interactive information system protocols, it is desirable to identify which protocol is in operation on a particular frequency and transport mechanism.
Because interactive information providers may provide interactive information for use over a wide geographic region, it would be cumbersome to require an information provider to identify all of this information for each user, and provide customized interactive information based upon the information identified.